Selection for the SAS is notoriously grueling, with only 10% of candidates succeeding. Operators endure extreme physical and mental tests, from long endurance marches in the Brecon Beacons to jungle ...

The selection process is seemingly tougher than ever.

British soldier Andy McNab became the youngest corporal in the army at the age of 19. Following eight years in the infantry, he joined the Special Air Service, or SAS, where he served for 10 years, ...

Relentless hill marches, hostile jungle combat and disorientating interrogation tactics are just a handful of the grim SAS selection tests used to transform regular soldiers into the toughest, ...